Was the forecast right for Seattle on Wed Sep 2?
Seattle, Washington · daily high temperature in °F · forecasts from each model's archived runs, verified against the SEA observations
10 days out, 4 models put Seattle's Wed Sep 2 high anywhere from 65° to 68°;by the final call, the day before, the field had settled to a median of 66°. The day verified at 70° against the SEA observations, with 0.23 in of precipitation — rain.
GFS landed closest, off by 1.3°. AIFS ran 7° cool.
What every model said, at every lead
Daily-high calls for Wed Sep 2 as each model's runs approached it — the last archived run per day. NBM and The Spread's own blend are consensus products and stay out of these ranges and rankings; the Seattle scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 10d · 2026-08-23 | 65° | 65° | 66° | — | 68° | — | — | 65–68° |
| 9d · 2026-08-24 | 66° | 62° | 67° | 64° | 77° | — | — | 62–77° |
| 8d · 2026-08-25 | 64° | 59° | 66° | 59° | 58° | — | — | 58–66° |
| 7d · 2026-08-26 | 63° | 57° | 62° | 68° | 63° | 61° | — | 57–68° |
| 6d · 2026-08-27 | 62° | 59° | 66° | 64° | 60° | 62° | 63° | 59–66° |
| 5d · 2026-08-28 | 61° | 63° | 70° | 61° | 67° | 64° | 63° | 61–70° |
| 4d · 2026-08-29 | 61° | 68° | 69° | 66° | 71° | 63° | 63° | 61–71° |
| 3d · 2026-08-30 | 63° | 65° | 65° | 66° | 67° | 64° | 62° | 62–67° |
| 2d · 2026-08-31 | 64° | 64° | 65° | 69° | 67° | 69° | 63° | 63–69° |
| 1d · 2026-09-01 | 63° | 65° | 65° | 68° | 69° | 66° | 68° | 63–69° |
| actual | 70° |
Read it honestly
This is one date, not a league table. A model can win a day it deserved to lose; rankings only mean something over a window. For that, see which model has been most accurate in Seattle — or every city The Spread scores.
Forecasts are what each model's archived runs said at the time, captured at The Spread's sweep times — never reconstructed after the fact. Truth is the SEA observations. The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.